/**
 * Copyright (C) 2002-2015   The FreeCol Team
 * <p>
 * This file is part of FreeCol.
 * <p>
 * FreeCol is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 * <p>
 * FreeCol is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * <p>
 * You should have received a copy of the GNU General Public License
 * along with FreeCol.  If not, see <http://www.gnu.org/licenses/>.
 */

package net.sf.freecol.common.option;

import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
import java.util.logging.Logger;

import javax.xml.stream.XMLStreamException;

import net.sf.freecol.common.io.FreeColXMLReader;
import net.sf.freecol.common.io.FreeColXMLWriter;
import net.sf.freecol.common.model.Specification;


/**
 * Represents an option where the valid choice is an integer and the
 * choices are represented by strings.  In general, these strings are
 * localized by looking up the key of the choice, which consists of
 * the identifier of the AbstractObject followed by a "." followed by
 * the value of the option string.  The automatic localization can be
 * suppressed with the doNotLocalize parameter, however.  There are
 * two reasons to do this: either the option strings should not be
 * localized at all (because they are language names, for example), or
 * the option strings have already been localized (because they do not
 * use the default keys, for example).
 */
public class SelectOption extends IntegerOption
{

    @SuppressWarnings( "unused" )
    private static final Logger logger = Logger.getLogger( SelectOption.class.getName( ) );

    /** Use localized labels? */
    protected boolean localizedLabels = false;

    /** A map of the valid values. */
    private final Map< Integer, String > itemValues
            = new LinkedHashMap<>( );


    /**
     * Creates a new <code>SelectOption</code>.
     *
     * @param specification The <code>Specification</code> to refer to.
     */
    public SelectOption( Specification specification )
    {
        super( specification );
    }


    /**
     * Gets the range values of this <code>RangeOption</code>.
     *
     * @return The value.
     */
    public Map< Integer, String > getItemValues( )
    {
        return itemValues;
    }

    /**
     * Add a new key,value pair to this option.
     *
     * @param key The key to add.
     * @param value The value to add.
     */
    public void addItemValue( Integer key, String value )
    {
        itemValues.put( key, value );
    }

    /**
     * Clear the item values for this option.
     *
     * Required by ClientOptions.fixClientOptions.
     */
    public void clearItemValues( )
    {
        itemValues.clear( );
    }

    /**
     * Whether the labels of this option need to be localized.  This is
     * not the case when the labels are just numeric values.
     *
     * @return True if localization is required.
     */
    public boolean localizeLabels( )
    {
        return localizedLabels;
    }

    /**
     * Gets the tag name of the item element.
     *
     * Should be overridden by subclasses to ensure read/writeChildren work.
     *
     * @return "selectValue".
     */
    public String getXMLItemElementTagName( )
    {
        return "selectValue";
    }

    // Interface Option

    /**
     * {@inheritDoc}
     */
    public void setValue( Integer value )
    {
        Set< Integer > keys = getItemValues( ).keySet( );
        if ( keys.isEmpty( ) ) return; // May not have been read yet

        Integer fallback = null;
        for ( Integer i : keys )
        {
            if ( i == value )
            { // Found a valid selection
                super.setValue( value );
                return;
            }
            if ( fallback == null ) fallback = i;
        }
        logger.warning( getXMLElementTagName( ) + ".setValue invalid value: "
                                + value + ", using fallback: " + fallback );
        super.setValue( fallback );
    }


    // Serialization

    private static final String LABEL_TAG = "label";
    private static final String LOCALIZED_LABELS_TAG = "localizedLabels";


    /**
     * {@inheritDoc}
     */
    @Override
    protected void writeAttributes( FreeColXMLWriter xw ) throws XMLStreamException
    {
        super.writeAttributes( xw );

        xw.writeAttribute( LOCALIZED_LABELS_TAG, localizedLabels );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void writeChildren( FreeColXMLWriter xw ) throws XMLStreamException
    {
        super.writeChildren( xw );

        for ( Map.Entry< Integer, String > entry : itemValues.entrySet( ) )
        {
            xw.writeStartElement( getXMLItemElementTagName( ) );

            xw.writeAttribute( VALUE_TAG, entry.getKey( ) );

            xw.writeAttribute( LABEL_TAG, entry.getValue( ) );

            xw.writeEndElement( );
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void readAttributes( FreeColXMLReader xr ) throws XMLStreamException
    {
        super.readAttributes( xr );

        localizedLabels = xr.getAttribute( LOCALIZED_LABELS_TAG, true );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void readChildren( FreeColXMLReader xr ) throws XMLStreamException
    {
        // We can not set the value until we have read the select options
        // so as to be able to check its validity.
        String value = xr.getAttribute( VALUE_TAG, ( String ) null );
        String defaultValue = xr.getAttribute( DEFAULT_VALUE_TAG, ( String ) null );

        // Clear containers.
        clearItemValues( );

        super.readChildren( xr );

        // Now we can correctly set the value.
        setValue( value, defaultValue );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void readChild( FreeColXMLReader xr ) throws XMLStreamException
    {
        final String tag = xr.getLocalName( );

        if ( getXMLItemElementTagName( ).equals( tag ) )
        {
            addItemValue( xr.getAttribute( VALUE_TAG, INFINITY ),
                          xr.getAttribute( LABEL_TAG, ( String ) null ) );
            xr.closeTag( tag );

        }
        else
        {
            super.readChild( xr );
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String toString( )
    {
        StringBuilder sb = new StringBuilder( 16 );
        sb.append( "[" ).append( getId( ) )
                .append( " value=" ).append( getValue( ) )
                .append( " localized=" ).append( localizedLabels )
                .append( "]" );
        return sb.toString( );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getXMLTagName( ) { return getXMLElementTagName( ); }

    /**
     * Gets the tag name of the root element representing this object.
     *
     * @return "selectOption".
     */
    public static String getXMLElementTagName( )
    {
        return "selectOption";
    }
}
